Learning in order to do

Leviticus 22:31

לא) וּשְׁמַרְתֶּם מִצְוֹתַי וַעֲשִׂיתֶם אֹתָם אֲנִי יְקֹוָק:
And you shall guard my commandments and do them! [For] I am Hashem.

Rashi explains:

לא) ושמרתם - זו המשנה ועשיתם - זה המעשה

Shmira is learning and Assia is action, doing the mitzvos.

I have always associated shmor with avoiding sins [Lavvin]. And Asei as command to fulfill mitzvos asei, positive mitzvot.

The super-commentaries discuss Rashi.

Sefer haZikaron suggests that Chazal quoted by Rashi are darshening the verse, because they thought the words in the verse redundant. If you are going to "do the mitzvot" than why do you also have to "watch them?" Therefore ushmartemm is giving you a different message.

Namely Ushmartem - zu haMishnah
Maskil LiDovid suggests that the main purpose of mishnah or learning is in order to guard and do.

This brings to mind the Mishnah in the 4th chapter of Avos:

רבי ישמעאל בנו אומר הלומד על מנת ללמד מספיקין בידו ללמוד וללמד
והלומד על מנת לעשות מספיקין בידו ללמוד וללמד לשמור ולעשות.

You'll notice that there is no option for learning as an intellectual exercise.
Truth demands action.
Action demands truth.

There must be balance of learning and action. One without the other is half a story.